Virginia Gov. Bob McDonnell likely didn’t quell a Republican backlash against him with a series of late-night amendments he added to legislation passed during the General Assembly session. But, analysts say, he also probably didn’t make things much worse.

Mr. McDonnell had until midnight Monday to sign, veto or amend hundreds of bills and at the same time potentially address a revolt against him within the conservative wing of his party upset that the $880 million bipartisan transportation package the governor shepherded through the legislature ran counter to his pledge not to raise taxes.

While he stopped short of any wholesale changes to a transportation plan that will likely be his signature legislative achievement, Mr. McDonnell proposed a series of modifications. The most serious of the changes he suggested was aimed at a major feature of the bill that caused Republican Attorney General and gubernatorial candidate Kenneth T. Cuccinelli II last week to declare the legislation unconstitutional.

Mr. Cuccinelli said provisions in the transportation bill imposing a .70 percent sales tax in Northern Virginia and Hampton Roads, as well as real estate recordation and hotel tax increases in Northern Virginia, were unconstitutional because they were not statewide and singled out particular areas for tax increases.Mr. McDonnell amended that part of the bill so that the regional tax could be imposed in any of the state’s 23 planning districts that meet certain criteria, which include factors such as population, the number of registered vehicles and transit trips. Currently under the formula only Northern Virginia and Hampton Roads qualify.

He also decreased a fee on hybrid vehicles from $100 to $64 and made slight downward adjustments to some tax rates.

“All together, it does the same good for transportation, but it ratchets down the tax burden,” Mr. McDonnell said Tuesday morning on the WTOP “Ask the Governor” program.

The delicate transportation compromise represented the first successful effort in decades to boost the state’s ebbing revenues for building new roads and repairing and maintaining existing ones. But longtime Virginia political observer Bob Holsworth said provisions that increase the state sales tax from 5 percent to 5.3 percent and impose the regional sales tax - added by legislators during negotiations - are ones that many Republicans are going to find “hard to swallow.”

“I think the people who were upset it was a tax are still going to be upset,” he said.

Mr. Holsworth said it was worth noting that the governor mentioned he had worked with Mr. Cuccinelli to address the concerns about the bill’s constitutionality and to avoid the possibility of lawsuits like those that doomed an aborted 2007 transportation proposal under Democratic former Gov. Tim Kaine that the Virginia Supreme Court struck down in 2008. But he pointed out that the officials had “reached some agreement on the constitutionality, not the advisability.”

Mr. Cuccinelli has publicly criticized the compromise plan, along with many conservatives.

Mr. McDonnell’s role in the plan’s passage was the likely reason that he was not invited to speak at the recent Conservative Political Action Conference. The blow to his conservative credentials was evident in the conference’s presidential straw poll, where he placed outside the top 10, a year after speaking at CPAC and being mentioned as a possible running mate or Cabinet member for 2012 GOP presidential nominee Mitt Romney.

Mr. Holsworth said many conservatives think Mr. McDonnell, who is believed to have presidential aspirations, “ceded the Republican brand by endorsing a tax increase.” He noted, though that the governor could just as easily emerge a political hero for chamber of commerce Republicans who could see him as a “courageous figure whose done the right thing for Virginia.”

“The governor’s taking a gamble here,” he said.

But while Mr. McDonnell might not have pleased fiscal conservatives, other actions were expected to be greeted with enthusiasm by social conservatives. The governor signed a bill requiring photo identification at the polls, after expressing concern that stricter ID laws could disenfranchise voters and open the state to possible lawsuits. The bill will still be subject to Justice Department review under Section 5 of the 1965 Voting Rights Act because of Virginia’s history of discrimination at the polls.

Mr. McDonnell also amended health reform legislation to prohibit abortion coverage through insurance plans purchased from the federally run health care exchange. Under the amendment, not only will insurers who are part of the federal exchange be unable to offer plans that cover abortion, they can’t write separate, optional riders covering it. The only coverage exceptions would be for rape, incest or to protect the life of a pregnant woman.

The amendment outraged abortion rights advocates and drew quick responses from Sen. Ralph S. Northam and Aneesh Chopra, Democrats seeking their party’s nomination for lieutenant governor. Mr. Northam of Norfolk, a children’s neurologist, said the move was an attempt to “appease the radical Ken Cuccinelli wing of the Republican Party.”

“He is trying to ban a basic and legal reproductive health care service that is already covered by nearly 90 percent of private insurance plans,” he said.

University of Richmond School of Law professor Carl Tobias pointed out the differing priorities of social conservatives and fiscal conservatives, noting that Mr. McDonnell throughout his term has “carried the water for social conservatives.”

“Everybody who’s in the base doesn’t necessarily agree on all these issues,” he said.

As far as the transportation plan is concerned, Mr. Tobias said getting results might be perceived as more important than Mr. McDonnell’s connection to a tax increase.

“I think he can play the pragmatist card and say, ‘Look, everyone who knows Virginia knows there was a real transportation problem, and that had to be solved,’ ” he said. “I think he can claim that he solved a real problem - or that he instituted measures that would solve that problem.”The legislature reconvenes for a single day on April 3 to consider the gubernatorial amendments and vetoes. Amendments may be rejected by a simple majority vote of at least 51 of the 100 House members and 21 of the 40 senators against the amendment. Overriding a veto requires two-thirds majorities in the House and the Senate. This article is based in part on wire service reports